Showing posts with label Tools. Show all posts
Showing posts with label Tools. Show all posts
Feb 23, 2012
How to test OS X Mountain Lion's Gatekeeper in Lion, (Wed, Feb 22nd)
How to test OS X Mountain Lion's Gatekeeper in Lion, (Wed, Feb 22nd): While I started working on comparing various OS X hardening guides (see the prior diary from a coupl ...(more)...
Sep 27, 2011
Geektool and Todotxt Desktop
I recently started using Geektool on my Mac for my background. I can't say enough about it. It really makes my desktop look nice. Apple should really look at incorporating this into the operating system if they haven't already.
One thing I have done that I haven't seen on many other examples is using the Todotxt todo list application for displaying my Todo list right on my desktop. I have it set to update every 30 seconds so it keeps things up to date and lets me know what to do next.
Just create a shell tool and have it run todo.sh. It is very simple and easy with no custom scripts or tools. Using custom shell scripts you could create many lists that display different projects, locations and priorities.
Here are a couple examples.
Tasks to do around the house:
todo ls @home
Stuff to do at work:
todo ls -@home
Buddhist task list:
todo ls @monastery + renunciation +harmlessness +goodwill
One thing I have done that I haven't seen on many other examples is using the Todotxt todo list application for displaying my Todo list right on my desktop. I have it set to update every 30 seconds so it keeps things up to date and lets me know what to do next.
Just create a shell tool and have it run todo.sh. It is very simple and easy with no custom scripts or tools. Using custom shell scripts you could create many lists that display different projects, locations and priorities.
Here are a couple examples.
Tasks to do around the house:
todo ls @home
Stuff to do at work:
todo ls -@home
Buddhist task list:
todo ls @monastery + renunciation +harmlessness +goodwill
Dec 27, 2010
Sysadmin Tools
50 UNIX / Linux Sysadmin Tutorials: "Merry Christmas and Happy Holidays to all TGS Readers. To wrap this year, I’ve collected 50 UNIX / Linux sysadmin related tutorials that we’ve posted so far. This is lot of reading. Bookmark this article for your future reference and read it whenever you get free time. Disk to disk backup using dd command: dd [...]
Read More: 50 UNIX / Linux Sysadmin Tutorials
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Get your copy of Vim 101 Hacks eBook.
Linux 101 Hacks eBook Password: linux-is-wonderful
Read More: 50 UNIX / Linux Sysadmin Tutorials
Copyright © The Geek Stuff. All Rights Reserved. Support us when you shop at amazon. Thank You!
Get your copy of Vim 101 Hacks eBook.
Linux 101 Hacks eBook Password: linux-is-wonderful
Nov 5, 2010
GeekDesk
GeekDesk: "
The GeekDesk is the best and most versatile desk I have found for my home office. It uses an electric motor to switch from sitting to standing position, and after nearly a year of using other standing desks I can say that it is one of the best investments anyone can make if they are interested in an adjustable desk.
My foray into standing desks began when I started working from home more often. I found that when I was sitting at work I would easily become distracted and more often than not lethargic. After reading several articles about the perils of sitting around all day I decided it was probably in my best interest to get a standing desk.
My first standing desk was a lectern I found on craigslist for $10. It was not adjustable, had an angled surface, and wasn't the best solution. But for the cost, it served me well. I learned how to stand all day, and the small footprint of the podium meant that I could keep my regular desk without sacrificing too much space. The difference between sitting and standing was immediately noticeable. I was much more likely to walk away from my desk and do something that needed to get done, I found that I didn't tire as much, and that my back no longer hurt from long days in a soft cushy chair. I was a standing desk convert.
Given the limitations of the lectern I then decided to replace it with a used AnthroCart desk: a solid American-made adjustable desk with an amazing life-time warranty. Seeing how it was adjustable I was able to fine-tune the height so that it made for easy typing. The desk was composed of three aluminum poles that have slots that range from 24' to 30' (and up to 48' with extensions) in height where you could screw the work surface in. It had a large 3'x3' flat surface that allowed me to add an external monitor and a printer to my setup. However, it also meant that I had to say goodbye to my chair and sitting desk. My conversion to full-time standing desk was pleasant, but there were times when I wished I could sit down to write longer pieces.
All of this explains why I am so happy to have discovered the GeekDesk. Simply put, it is a traditional two-legged desk frame that uses an electric motor to raise or lower the working surface from 26' to 46.5' and anywhere in-between. It can lift up to 175 pounds, and it rises and falls at 1' per second.
The desk itself is made up of two steel legs connected by a cross bar that contains the electric motor and rack-and-pinion lift mechanism. The top of the desk is screwed on to the legs. GeekDesk sells the legs separately for those interested in attaching their own surface.
I have the slightly smaller GeekDesk Mini. It is identical to the GeekDesk except that it comes with a shorter crossbar that is 37.75' wide compared to the standard 61.42' model. It is more than enough space for me as I have a fairly compact setup including a 15' laptop, and a 24' external monitor.
To raise or lower the desk there are controls attached to the underside of the working surface. They remain out of the way, and are very easy to use. Simply push the button to activate, and click up or down on the toggle. It is a smooth movement and you can do it with everything on your desk without a fear of spills, or toppling monitors.
While my AnthroCart desk served me well, I realized that having the versatility of being able to sit and stand at the same workspace was really valuable to me. The biggest downside of this flexibility is that the temptation to sit is ever present. Since adopting the GeekDesk I do find myself sitting down more often than I would if I didn't have the option. I am undecided about whether this is a good or bad thing, but if you find that you have low self control then it is possible this desk isn't for you.
I love being able to sit and stand at my workspace, and I believe it has improved my general well being and happiness while working from home. A word of warning: anybody interested in switching to standing all day should, as with anything bio-mechanical, take it slow and make sure not to cause too much strain. I have had friends who have made the switch too quickly complain about back strain, foot pain, and tired legs. This goes away, but can easily be avoided by slowly easing into standing all day. And I strongly believe the GeekDesk represents one of the absolute best ways to do so.
-- Oliver Hulland
GeekDesk Mini
$525 for the frame (plus $85-$180 for shipping)
$749 for the frame and top (plus $110-$310 for shipping)
GeekDesk Original
$799 for the frame and top (plus $110-$310 for shipping)"
The GeekDesk is the best and most versatile desk I have found for my home office. It uses an electric motor to switch from sitting to standing position, and after nearly a year of using other standing desks I can say that it is one of the best investments anyone can make if they are interested in an adjustable desk.
My foray into standing desks began when I started working from home more often. I found that when I was sitting at work I would easily become distracted and more often than not lethargic. After reading several articles about the perils of sitting around all day I decided it was probably in my best interest to get a standing desk.
My first standing desk was a lectern I found on craigslist for $10. It was not adjustable, had an angled surface, and wasn't the best solution. But for the cost, it served me well. I learned how to stand all day, and the small footprint of the podium meant that I could keep my regular desk without sacrificing too much space. The difference between sitting and standing was immediately noticeable. I was much more likely to walk away from my desk and do something that needed to get done, I found that I didn't tire as much, and that my back no longer hurt from long days in a soft cushy chair. I was a standing desk convert.
Given the limitations of the lectern I then decided to replace it with a used AnthroCart desk: a solid American-made adjustable desk with an amazing life-time warranty. Seeing how it was adjustable I was able to fine-tune the height so that it made for easy typing. The desk was composed of three aluminum poles that have slots that range from 24' to 30' (and up to 48' with extensions) in height where you could screw the work surface in. It had a large 3'x3' flat surface that allowed me to add an external monitor and a printer to my setup. However, it also meant that I had to say goodbye to my chair and sitting desk. My conversion to full-time standing desk was pleasant, but there were times when I wished I could sit down to write longer pieces.
All of this explains why I am so happy to have discovered the GeekDesk. Simply put, it is a traditional two-legged desk frame that uses an electric motor to raise or lower the working surface from 26' to 46.5' and anywhere in-between. It can lift up to 175 pounds, and it rises and falls at 1' per second.
The desk itself is made up of two steel legs connected by a cross bar that contains the electric motor and rack-and-pinion lift mechanism. The top of the desk is screwed on to the legs. GeekDesk sells the legs separately for those interested in attaching their own surface.
I have the slightly smaller GeekDesk Mini. It is identical to the GeekDesk except that it comes with a shorter crossbar that is 37.75' wide compared to the standard 61.42' model. It is more than enough space for me as I have a fairly compact setup including a 15' laptop, and a 24' external monitor.
To raise or lower the desk there are controls attached to the underside of the working surface. They remain out of the way, and are very easy to use. Simply push the button to activate, and click up or down on the toggle. It is a smooth movement and you can do it with everything on your desk without a fear of spills, or toppling monitors.
While my AnthroCart desk served me well, I realized that having the versatility of being able to sit and stand at the same workspace was really valuable to me. The biggest downside of this flexibility is that the temptation to sit is ever present. Since adopting the GeekDesk I do find myself sitting down more often than I would if I didn't have the option. I am undecided about whether this is a good or bad thing, but if you find that you have low self control then it is possible this desk isn't for you.
I love being able to sit and stand at my workspace, and I believe it has improved my general well being and happiness while working from home. A word of warning: anybody interested in switching to standing all day should, as with anything bio-mechanical, take it slow and make sure not to cause too much strain. I have had friends who have made the switch too quickly complain about back strain, foot pain, and tired legs. This goes away, but can easily be avoided by slowly easing into standing all day. And I strongly believe the GeekDesk represents one of the absolute best ways to do so.
-- Oliver Hulland
GeekDesk Mini
$525 for the frame (plus $85-$180 for shipping)
$749 for the frame and top (plus $110-$310 for shipping)
GeekDesk Original
$799 for the frame and top (plus $110-$310 for shipping)"
Oct 12, 2010
Host File Kung Fu
MVPS Custom Host File Instructions
I've been using a custom host file on my workstation for quite a while now. It works really well in blocking all sorts of undesired activity. Of course I only have 3 lines to block specific advertising sites but the potential is endless. Such a small change to my local configuration makes such a huge difference in all aspects of online activity.
If you are familiar with the NoScript or AdBlock plugins for Firefox then you are familiar with the concept of blocking certain domains, URLs or DNS names. Your host file is just an extension of how this works. Only instead of doing it at the application level, it does it at the operating system level.
Any time your machine tries to access a resource on the network, it has to translate that network address from a name to a number. If that process doesn't work (or is told to look in the wrong place) the resource isn't found. If that process is a looking for an advertisement or a nasty script, then that resource fails to load. When that resource fails to load it frees up resources on your machine to load more important stuff, like that article on how to winterize your lawn. Your host file just tells your machine to look in the wrong places for specific resources since any resource at this specific location is known to be undesired.
I use Open DNS at home to block a lot of these sites but this doesn't help when you leave the safety and comfort of your home network.
There are multiple sites out there that help with custom host files but MVPS is one of the best. Please take a look and see what they have to offer.
I've been using a custom host file on my workstation for quite a while now. It works really well in blocking all sorts of undesired activity. Of course I only have 3 lines to block specific advertising sites but the potential is endless. Such a small change to my local configuration makes such a huge difference in all aspects of online activity.
If you are familiar with the NoScript or AdBlock plugins for Firefox then you are familiar with the concept of blocking certain domains, URLs or DNS names. Your host file is just an extension of how this works. Only instead of doing it at the application level, it does it at the operating system level.
Any time your machine tries to access a resource on the network, it has to translate that network address from a name to a number. If that process doesn't work (or is told to look in the wrong place) the resource isn't found. If that process is a looking for an advertisement or a nasty script, then that resource fails to load. When that resource fails to load it frees up resources on your machine to load more important stuff, like that article on how to winterize your lawn. Your host file just tells your machine to look in the wrong places for specific resources since any resource at this specific location is known to be undesired.
I use Open DNS at home to block a lot of these sites but this doesn't help when you leave the safety and comfort of your home network.
There are multiple sites out there that help with custom host files but MVPS is one of the best. Please take a look and see what they have to offer.
Oct 4, 2010
Safe Browsing Alerts for Network Administrators
Safe Browsing Alerts for Network Administrators: "Posted by Nav Jagpal and Ke Wang, Security Team
Google has been working hard to protect its users from malicious web pages, and also to help webmasters keep their websites clean. When we find malicious content on websites, we attempt to notify their webmasters via email about the bad URLs. There is even a Webmaster Tools feature that helps webmasters identify specific malicious content that has been surreptitiously added to their sites, so that they can clean up their site and help prevent it from being compromised in the future.
Today, we’re happy to announce Google Safe Browsing Alerts for Network Administrators -- an experimental tool which allows Autonomous System (AS) owners to receive early notifications for malicious content found on their networks. A single network or ISP can host hundreds or thousands of different websites. Although network administrators may not be responsible for running the websites themselves, they have an interest in the quality of the content being hosted on their networks. We’re hoping that with this additional level of information, administrators can help make the Internet safer by working with webmasters to remove malicious content and fix security vulnerabilities.
To get started, visit safebrowsingalerts.googlelabs.com.
Google has been working hard to protect its users from malicious web pages, and also to help webmasters keep their websites clean. When we find malicious content on websites, we attempt to notify their webmasters via email about the bad URLs. There is even a Webmaster Tools feature that helps webmasters identify specific malicious content that has been surreptitiously added to their sites, so that they can clean up their site and help prevent it from being compromised in the future.
Today, we’re happy to announce Google Safe Browsing Alerts for Network Administrators -- an experimental tool which allows Autonomous System (AS) owners to receive early notifications for malicious content found on their networks. A single network or ISP can host hundreds or thousands of different websites. Although network administrators may not be responsible for running the websites themselves, they have an interest in the quality of the content being hosted on their networks. We’re hoping that with this additional level of information, administrators can help make the Internet safer by working with webmasters to remove malicious content and fix security vulnerabilities.
To get started, visit safebrowsingalerts.googlelabs.com.
Aug 24, 2010
Five awesome Automator tips
Five awesome Automator tips: "Think Apple’s built-in automation tool, Automator, is more trouble than it's worth? Think again. Not only can Automator perform wondrous feats, but with these tips it's also easy to make it happen.
"
"
Jun 23, 2010
Home Network Filtering Service from OpenDNS
More great services from OpenDNS.
FamilyShield is a No-Setup Adult Content Blocker for Your Router [Content Filtering]: "
OpenDNS already offered a great content filtering tool that you could set up on your home Wi-Fi router. Now the DNS provider is making it easier to block impressionable eyes from adult content—and clever proxies and other work-arounds, too. More »
FamilyShield is a No-Setup Adult Content Blocker for Your Router [Content Filtering]: "
OpenDNS already offered a great content filtering tool that you could set up on your home Wi-Fi router. Now the DNS provider is making it easier to block impressionable eyes from adult content—and clever proxies and other work-arounds, too. More »
Apr 19, 2010
Use an Ubuntu Live CD to Securely Wipe Your PC’s Hard Drive [Hard Drives]
Use an Ubuntu Live CD to Securely Wipe Your PC’s Hard Drive [Hard Drives]:
We've highlighted options for properly erasing your hard drives in the past (some simple, some involving hammers); in a similar vein, our friends at How-To Geek dive into the specifics of securely wiping your hard drive with an Ubuntu Live CD. More »
We've highlighted options for properly erasing your hard drives in the past (some simple, some involving hammers); in a similar vein, our friends at How-To Geek dive into the specifics of securely wiping your hard drive with an Ubuntu Live CD. More »
Mar 24, 2010
Mar 11, 2010
Save Disk Space in OS X: Monolingual
I am always amazed at how much space the Multi-Lingual files take up when installing OS X (let's not mention the print drivers). So why should I be surprised when I save so much space using this application? It managed to trim off 2.3GB in just a few minutes. That's not a lot in this era of 500GB drives but every little bit helps. That's a whole movie burned to disk!
I know I should be ashamed for using the default install in the first place. Like everyone who gets a new MacBookPro I was a little eager to start using it. The last thing I wanted to do was wait for a new install. Now if it was a new Dell it would be a different story. I have no qualms about booting right from a DVD when a new Dell shows up.
http://monolingual.sourceforge.net/
Thanks Tyler!
I know I should be ashamed for using the default install in the first place. Like everyone who gets a new MacBookPro I was a little eager to start using it. The last thing I wanted to do was wait for a new install. Now if it was a new Dell it would be a different story. I have no qualms about booting right from a DVD when a new Dell shows up.
http://monolingual.sourceforge.net/
Thanks Tyler!
Nov 12, 2009
Microsoft Steady State
For years I have replied upon the Faronic's product, DeepFreeze, for supporting public computer labs. Recently I found Microsoft Steady State and it looks promising. One of the problems I recently ran into with DeepFreeze was the lack of interaction with the operating system. This can be good in some cases but bad in others. I am hoping that Microsoft has solved some of these issues Steady State seeing as they have pretty good access to the code. Hopefully I can post some results here when I get the chance.
Online Charts and Diagrams
Lovely Charts is a great online resource for creating a number of quality online flowcharts, network diagrams and the like. The free account allows you to save one project on the site. You can still create new projects and save/export them as much as you like. You can only save one though. If you update your account (for a very reasonable fee) you can save many projects and edit them online.
It's a very useful tool for those of us who rarely dabble in the art of network diagrams and flowcharts but sometimes need a graphic to support an idea to upper management. Let's face it, Visio just isn't worth it and there are few substitutes. This is a great one.
It's a very useful tool for those of us who rarely dabble in the art of network diagrams and flowcharts but sometimes need a graphic to support an idea to upper management. Let's face it, Visio just isn't worth it and there are few substitutes. This is a great one.
Nov 5, 2009
Google Dashboard - For all your Google Settings
I never really thought it was hard to manage this stuff before. Perhaps I will find something new. Still this is a great idea for heavy Google users.
Transparency, choice and control - now complete with a Dashboard!: "Posted by Alma Whitten, Software Engineer, Yariv Adan, Product Manager, and Marissa Mayer, VP of Search Products and User Experience
(Cross-posted from the Official Google Blog.)
Transparency, choice and control - now complete with a Dashboard!: "Posted by Alma Whitten, Software Engineer, Yariv Adan, Product Manager, and Marissa Mayer, VP of Search Products and User Experience
(Cross-posted from the Official Google Blog.)
Today, we are excited to announce the launch of Google Dashboard. Have you ever wondered what data is stored with your Google Account? The Google Dashboard offers a simple view into the data associated with your account — easily and concisely in one location.
Over the past 11 years, Google has focused on building innovative products for our users. Today, with hundreds of millions of people using those products around the world, we are very aware of the trust that you have placed in us, and our responsibility to protect your privacy and data. In the past, we've taken numerous steps in this area, investing in educating our users with our Privacy Center, making it easier to move data in and out of Google with our Data Liberation Front, and allowing you to control the ads you see with interest-based advertising. Transparency, choice and control have become a key part of Google's philosophy, and today, we're happy to announce that we're doing even more.
In an effort to provide you with greater transparency and control over their own data, we've built the Google Dashboard. Designed to be simple and useful, the Dashboard summarizes data for each product that you use (when signed in to your account) and provides you direct links to control your personal settings. Today, the Dashboard covers more than 20 products and services, including Gmail, Calendar, Docs, Web History, Orkut, YouTube, Picasa, Talk, Reader, Alerts, Latitude and many more. The scale and level of detail of the Dashboard is unprecedented, and we're delighted to be the first Internet company to offer this — and we hope it will become the standard. Watch this quick video to learn more and then try it out for yourself at www.google.com/dashboard.
Over the past 11 years, Google has focused on building innovative products for our users. Today, with hundreds of millions of people using those products around the world, we are very aware of the trust that you have placed in us, and our responsibility to protect your privacy and data. In the past, we've taken numerous steps in this area, investing in educating our users with our Privacy Center, making it easier to move data in and out of Google with our Data Liberation Front, and allowing you to control the ads you see with interest-based advertising. Transparency, choice and control have become a key part of Google's philosophy, and today, we're happy to announce that we're doing even more.
In an effort to provide you with greater transparency and control over their own data, we've built the Google Dashboard. Designed to be simple and useful, the Dashboard summarizes data for each product that you use (when signed in to your account) and provides you direct links to control your personal settings. Today, the Dashboard covers more than 20 products and services, including Gmail, Calendar, Docs, Web History, Orkut, YouTube, Picasa, Talk, Reader, Alerts, Latitude and many more. The scale and level of detail of the Dashboard is unprecedented, and we're delighted to be the first Internet company to offer this — and we hope it will become the standard. Watch this quick video to learn more and then try it out for yourself at www.google.com/dashboard.
Sep 19, 2009
Sysinternals Updates
The well know Sysinternals Tools have been updated and SANS has a great link to all the good stuff.
Sep 9, 2009
Basic Raid Level Information
I found this information helpful so, as usual, I copied it somewhere I can find it quickly. There is always the Wikipedia RAID page as well.
In the IT world, hardware failure is not about if it will happen, but when it will happen. If you run a server that has any sort of important data on it, protection of that data is very important. Many people chose to implement a redundant RAID (redundant array of independent disks) array to help deal with the risk of having a hardware failure. There are several types of RAID that are appropriate for servers, and there are several ways they can be effectively implemented.
IBM patented the idea of RAID in 1978. It was not until 1988 that the RAID levels that we have come to know were defined. This development was done at University of California in Berkeley. Now days RAID is used in many servers throughout the world and even in desktop machines.
RAID 1
The use of a mirroring RAID array, or RAID 1 is useful in server situations. It creates an exact copy of the original drive. If either of the drives fail, the system can continue operations without any downtime. Then the new hard drive can be put into the system and it can rebuild the array.
This system is considered a little less desirable than a RAID 5 setup for most situations of day-to-day operation. However, it has several applications where the use of RAID 1 can be beneficial. One advantage is that it has a faster seek time than RAID 5, which makes it beneficial for data that, will not be written to often. The main advantage is that some 1U servers do not have room for a 3 drive array, so implementing RAID 1 is often considered better for reliability than no RAID at all. However, the most useful way that I have seen RAID 1 used in the real world is as backups. With a hot-swappable setup, the mirror disk can be removed and kept as backup much the same way as a tape backup can be stored. This proves to be very useful for mission critical systems since it allows for a system to be brought back online after a data failure, or the system to be brought up on separate hardware after a catastrophic hardware failure.
RAID 5
Probably the most common disk array used in enterprise computing is a RAID 5 array. This is because it maximizes disk usage, reliability, and speed of access. To get an idea of how it works, there are usually 3 drives in an array that each have their data divided between two other drives.
On mission critical servers, RAID 5 is often used with a cache that has an attached battery backup. This ensures that in a power failure, no transactions are lost from the server. Often times database servers with high amounts of transactions will have a battery unit since the RAID card would cache transactions before waiting, a power failure could result in an inconsistent database or critical data loss.
RAID 10
This type of RAID array requires 4 or more drives. At the top level is a RAID 0 array which combines lower level RAID 1 arrays. This type of RAID array has a benefit over RAID 5 in that it has faster write times. This often makes it a little bit better of a choice than RAID 5 for database servers.
Space Calculations
To calculate RAID 1 you simply divide the total drive space by 2. For RAID 5 you multiply the total space of the drives by the number of drives over 1 to get total usable space. Then for RAID 10 you add up each RAID 1 array.
RAID1
2 80 GB Drives
80/2=80
RAID5
3 80 GB Drives
240*(2/3)=160
5 80 GB Drives
400*(4/5)=320
RAID10
4 80GB Drives
2 RAID 1 Arrays = 160GB usable
Hardware RAID
The use of hardware RAID arrays no longer makes as much sense as it once did. There are still reasons to use a hardware RAID over a software RAID. The first reason to use hardware RAID is that it usually has a cache, which speeds up the operation of the array dramatically. The second advantage is that it will not cut into system resources as much as software RAID. The biggest advantage is in the possibility of having a battery backed up cache. This will help prevent corruption from an unexpected power issue or a system crash.
Software RAID
Although historically all RAID arrays were completely hardware based, there is a growing popularity of software RAID. One of the reasons for this is that CPU speeds are now fast enough that the processing time involved managing the RAID array is really minimal compared to the overall processor.
One of the major advantages of software RAID is that it can be setup on commodity hardware so the physical disks can easily be moved to another server in the event of a hardware failure that does not involve the disks. The biggest disadvantage is that software raid has no cache so the limit to the speed data can flow from the Operating System is the limit of the drives.
Notifications
Lets assume you have a working RAID setup now. Now if a drive fails the system continues like nothing ever happened. The problem is, without notification of a drive failure, there is no reason to have raid. So make sure you setup a system to notify you whenever a drive fails. It may notify you by email, page you, or on some control panel. The important thing is that you know before two drives fail and render the array useless.
Conclusion
Hopefully you will be able to make some important purchasing decisions for you next server after reading this article. There are a lot of things to consider when planning data availability so make sure you spend enough time to get everything right. Remember that no single RAID setup is best for all applications.
by Tyler Weaver
In the IT world, hardware failure is not about if it will happen, but when it will happen. If you run a server that has any sort of important data on it, protection of that data is very important. Many people chose to implement a redundant RAID (redundant array of independent disks) array to help deal with the risk of having a hardware failure. There are several types of RAID that are appropriate for servers, and there are several ways they can be effectively implemented.
IBM patented the idea of RAID in 1978. It was not until 1988 that the RAID levels that we have come to know were defined. This development was done at University of California in Berkeley. Now days RAID is used in many servers throughout the world and even in desktop machines.
RAID 1
The use of a mirroring RAID array, or RAID 1 is useful in server situations. It creates an exact copy of the original drive. If either of the drives fail, the system can continue operations without any downtime. Then the new hard drive can be put into the system and it can rebuild the array.
This system is considered a little less desirable than a RAID 5 setup for most situations of day-to-day operation. However, it has several applications where the use of RAID 1 can be beneficial. One advantage is that it has a faster seek time than RAID 5, which makes it beneficial for data that, will not be written to often. The main advantage is that some 1U servers do not have room for a 3 drive array, so implementing RAID 1 is often considered better for reliability than no RAID at all. However, the most useful way that I have seen RAID 1 used in the real world is as backups. With a hot-swappable setup, the mirror disk can be removed and kept as backup much the same way as a tape backup can be stored. This proves to be very useful for mission critical systems since it allows for a system to be brought back online after a data failure, or the system to be brought up on separate hardware after a catastrophic hardware failure.
RAID 5
Probably the most common disk array used in enterprise computing is a RAID 5 array. This is because it maximizes disk usage, reliability, and speed of access. To get an idea of how it works, there are usually 3 drives in an array that each have their data divided between two other drives.
On mission critical servers, RAID 5 is often used with a cache that has an attached battery backup. This ensures that in a power failure, no transactions are lost from the server. Often times database servers with high amounts of transactions will have a battery unit since the RAID card would cache transactions before waiting, a power failure could result in an inconsistent database or critical data loss.
RAID 10
This type of RAID array requires 4 or more drives. At the top level is a RAID 0 array which combines lower level RAID 1 arrays. This type of RAID array has a benefit over RAID 5 in that it has faster write times. This often makes it a little bit better of a choice than RAID 5 for database servers.
Space Calculations
To calculate RAID 1 you simply divide the total drive space by 2. For RAID 5 you multiply the total space of the drives by the number of drives over 1 to get total usable space. Then for RAID 10 you add up each RAID 1 array.
RAID1
2 80 GB Drives
80/2=80
RAID5
3 80 GB Drives
240*(2/3)=160
5 80 GB Drives
400*(4/5)=320
RAID10
4 80GB Drives
2 RAID 1 Arrays = 160GB usable
Hardware RAID
The use of hardware RAID arrays no longer makes as much sense as it once did. There are still reasons to use a hardware RAID over a software RAID. The first reason to use hardware RAID is that it usually has a cache, which speeds up the operation of the array dramatically. The second advantage is that it will not cut into system resources as much as software RAID. The biggest advantage is in the possibility of having a battery backed up cache. This will help prevent corruption from an unexpected power issue or a system crash.
Software RAID
Although historically all RAID arrays were completely hardware based, there is a growing popularity of software RAID. One of the reasons for this is that CPU speeds are now fast enough that the processing time involved managing the RAID array is really minimal compared to the overall processor.
One of the major advantages of software RAID is that it can be setup on commodity hardware so the physical disks can easily be moved to another server in the event of a hardware failure that does not involve the disks. The biggest disadvantage is that software raid has no cache so the limit to the speed data can flow from the Operating System is the limit of the drives.
Notifications
Lets assume you have a working RAID setup now. Now if a drive fails the system continues like nothing ever happened. The problem is, without notification of a drive failure, there is no reason to have raid. So make sure you setup a system to notify you whenever a drive fails. It may notify you by email, page you, or on some control panel. The important thing is that you know before two drives fail and render the array useless.
Conclusion
Hopefully you will be able to make some important purchasing decisions for you next server after reading this article. There are a lot of things to consider when planning data availability so make sure you spend enough time to get everything right. Remember that no single RAID setup is best for all applications.
by Tyler Weaver
Sep 2, 2009
Flowcharts for Computer Troubleshooting
I've always wanted to make something like this but never had the time (from Lifehacker)
We recently showed you a fun (but accurate) tech support cheat sheet courtesy of popular web comic xkcd. If hardware is more your problem, this series of (non-comic) interactive charts can help you troubleshoot some common hardware problems.
We recently showed you a fun (but accurate) tech support cheat sheet courtesy of popular web comic xkcd. If hardware is more your problem, this series of (non-comic) interactive charts can help you troubleshoot some common hardware problems.
The flowcharts are the creation of author Morris Rosenthal. Morris has created detailed, interactive charts for everything from hard drive failure to CD and DVD troubleshooting to modem failure.
I'm by no means the resident hardware expert at Lifehacker HQ, but the charts offer an easy way to diagnose and resolve some basic problems for anyone from beginners to the more hardware-savvy folks out there.
Hit up the link to see all eight diagnostic charts in action.
Google Apps News
Nice, I've been looking forward to trying out Wave.
Google to let Apps users try out Wave: "Google plans to let Apps users test its Wave collaboration and communication tool, which is still in development.
Google to let Apps users try out Wave: "Google plans to let Apps users test its Wave collaboration and communication tool, which is still in development.
Aug 29, 2009
WinToFlash Turns Your Windows Installation DVD into a USB-based Installer [Downloads]
WinToFlash Turns Your Windows Installation DVD into a USB-based Installer [Downloads]
Windows: Want to turn your Windows installation DVD into an installation flash drive? WinToFlash can do that and more.
WinToFlash can transfer Windows XP, Vista, and 7 onto a flash drive as well as Server 2003 and 2008. WinToFlash can also transfer Windows Preinstallation Environments to flash drive.
The process is simple and mostly obvious. You tell WinToFlash where the installation files you want to transfer are located and either let the transfer wizard take care of things, or specify settings like what kind of format the flash drive will undergo. In our test using a USB 2.0 generic flash drive it took about 12 minutes to turn a Windows 7 installation DVD into a USB-based installer.
WinToFlash is freeware, Windows only.
Jul 28, 2009
NoScript to the Rescue, Again
Slashdot is running a scary but true story, 92% of Windows PCs Vulnerable To Zero-Day Attacks On Flash. Now is the time for NoScript to come to the aid of just about everyone.
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